The University of Massachusetts Amherst campus. The UMass system would be allowed to keep tuition revenue that campuses collect from in-state students under a proposal Senate leaders plan to insert into a $361 million midyear spending bill.
(John Suchocki)

Federal investigators in 2011 pledged to do a better job monitoring how colleges were handling sexual assault complaints. That's when they started looking into whether institutions, including the University of Massachusetts Amherst, had complied with Title IX in dealing with earlier complaints.

Four years and six months later, that UMass investigation is still ongoing.

According to a new Chronicle of Higher Education database of the federal investigations, the review of UMass Amherst's process is the longest unresolved Title IX sexual violence investigation in the country.

UMass spokesman Edward Blaguszewski told Boston.com that the case is not due to a complaint from a student about the handling of a sexual assault complaint, but was launched as part of a standard Title IX compliance review. Title IX is the federal gender equity law.

"Meanwhile, the university has been working on an ongoing basis to update and revise its Title IX grievance resolution policies and procedures, and we launched a comprehensive new Title IX resources website last fall," Blaguszewski told the website. "We look forward to the Office of Civil Rights reaching a conclusion in its review of the UMass matter."

A new investigation into a possible Title IX violation at the university was opened in September 2015, according to The Chronicle's database.

The Chronicle reported that only 19 percent of the 243 investigations opened since the crackdown in 2011 have been resolved.

Massachusetts colleges and universities appear on the list of open investigations.

The oldest investigations in the state after the one at UMass Amherst are from December 2013 at Boston University and Emerson College.

An Amherst College investigation was opened in January 2014. Investigations at Hampshire College, UMass Dartmouth, Harvard University and the Berklee College of Music were opened in June and July of 2014.

In August 2015, investigations were opened at the Massachusetts Institute of Technology and Tufts University. The most recent reviews opened in Massachusetts were in December 2015 at Western New England University and Boston College.

A four-month investigation at the Massachusetts Maritime Academy was closed in 2012.

Boston.com reported that there are currently 197 open investigations at 161 institutions nationwide.

The Chronicle reported that a backlog of cases is making it hard for the federal civil rights office to resolve them.

The publication said that President Barack Obama's 2016 budget request includes $131 million for the office, which could be used to hire another 200 full-time employees.

Assistant Secretary for Civil Rights Joseph Leonard Jr. said he could use 500, the Chronicle reported.